This invention relates to fine granular metallic powder particles of a ductile and/or malleable material and to the process for producing the particles. More particluarly it relates to powder particles having an aspect ratio of from greater than 1 to about 100 and a means particle size of less than about 20 micrometers in diameter. More particularly, the process involves a grinding technique in which the grinding media are constrained to remain in a high density packed state.
Prior art methods of attritor, rotary, or vibratory ball milling produce very flaky high aspect ratio material which is difficult to feed to a plasma jet because of its low packing density and particle morphology.
It is desirable to produce a granular material because granular morphology results in a material with substantially higher bulk density and feeds to a plasma jet with greater ease, that is, a with a higher feed rate than non-granular or flaky material. The granular morphology also allows the material to be used in milled form for press and sinter applications including permanent metal filters.